Here are the Pwins to date. Giants need to get their act together and stop winning these games by 1 run.

Remember. Weak teams will always be "due" wins, because they still score. Same goes for very good teams. They will still get scored on and will always be "due" losses. And, well, if weak teams are still "due" some losses (twins), then they are still overperforming- even with a low win percentage so we can find value betting against these teams. We are on the Twins today cause they are playing the Orioles, which I believe need to regress faster than the Twins. Especially with the lowest Pwin.

Teams who have a yellow highlight in the win percentage are within two deviations away from average.

Saturday, April 14, 2012

Alright. Before I start on Pythagorean Part Deux, let's take a look at that last example. Bruins vs Lightning, 3/13/12. Final score: Bruins 1 - Lightning 6. But the Bruins had a 7.53 Pwin advantage that night. In the previous post, I mentioned that Pwin is the first filter and other statistics must be considered. Here are the other contributing factors (more detail for some of these in later posts):

Schedule

Bruins played their 4th game in 6 nights and had back to back away games. They just played a tough game against playoff contender Pittsburgh Penguins. Lightning played their 3rd game in 6 nights and 1st in 3 nights. Lightning been at home after 3/8/12 game against Washington Capitals. Plenty of rest.

Injuries

Key player for Bruins (Nathan Horton) out with concussion since January. Before injury Horton's concussion, Bruins were 31-13-2. After concussion (to end of regular season), 18-16-2. Go figure. Starting goalie Tim Thomas needed rest. Backup goalie Tuukka Rask has an injury to left leg. In comes 3rd string goalie Marty Turco to start. He is garbage by the way. The guy was signed by the Bruins a week earlier, and this game was his first start as a Bruin. He allowed 3 goals within the first 5 minutes. Needless to say, the game was over in the first period as the Lightning scored 4 goals in 10 shots.

Monday, March 12, 2012

Wanted to get out another example about Pythagorean Expectation. The San Francisco Giants' 2011 Season. Unless you are also a Giants fan, I cannot even begin to tell you how damn stressful it is to watch these games sometimes. They are torture. I don't know how many hours of sleep I've lost. Leading 3-2 in the bottom of the 9th. Brian Wilson on the mound. Walk. Out. Out. Walk. Walk. Pitch count 3-2. Foul. Foul. Foul. Strike Three. Whew. That's Giants baseball. One run squeakers. We can do this all season. Not. They were just setting themselves up for an epic fail. Let's take a look at the season ending numbers.

No surprise to anyone who follows baseball. The Giants were one of the bottom-feeders in offense. Third to last in my ratings. However, they maneuvered themselves into 86-76 record.... scoring ONLY 3.52 runs per game. That's 570 runs scored all season. And how many runs do they allow? 578. Now what does that tell us?

How do the Giants have a positive winning record? They allowed more runs than they scored. What happens when you allow more runs? You lose. With 570 runs scored and 578 runs allowed, the Giants end with a PW% of 0.494. This translates to a Pwin of 79.97 games, giving us a Pdiff of -6.03. From what I remember, they already had a Pdiff of about -5.0 (estimate) at the All-Star Break. The Arizona Diamondbacks however, had a positive Pdiff. The SF Giants were not going to repeat as Division Champions (although it got close at the end as the Dbacks tried to screw themselves over as well).

If you updated the stats daily, you can see the Pdiff for the Giants progressively grow bigger and bigger in the negative with all of their one-two run wins. When they lose a game, they would not lose by one. They lose by three, seven, thirteen. What happens as we allow more runs in the equation? The denominator gets bigger, giving us a lower win percentage. And then we lose. We lose. We lose. Alright, I'm done ranting. Peace.

Let's
start with the most basic of basics. How does a team win? Score more runs (or goals,
points) than the opponent, and allow fewer runs than the opponent. That is true
in any given game. It is also the same
over the course of a season. The team with the better run differential has a
better tendency to win because they score more than they allow. With this
concept, the following formula known as the Pythagorean Expectation was created:

PW% = PSx / (PSx + PAx)

where PW% = Pythag win percentage

PS = Runs/Goals/Points scored

PA = Runs/Goals/Points allowed

x = 1.82 for MLB, 2.0 for NHL, 2.37 for NFL and 13.91 for NBA. More of this later.

This formula approximates a team's win percentage based on their scoring capability. Using this approximation, we can compare it to the team's actual win percentage and determine whether a team has been "lucky" or "unlucky" and whether they have been under performing or over performing. Let's take a look at an example on how Pythag is calculated:

As of 3/12/12, the Boston Bruins (40-28) scored 222 goals and allowed 164 goals. Plugging in the numbers, this gives the Bruins a PW% of 0.647 as opposed to their actual win percentage of 0.588. This implies that the Bruins were either under performing or unlucky. Have they been getting a lot of bad breaks? Have they been lackadaisical in their games? Have injuries become a factor? Eventually, this "luck" will even itself out and regress to the Pythagorean Expectation. A PW% of 0.647 suggests that Bruins are really a 44 win team with 24 losses. PW% = 0.5, when PS = PA.

Using this theory, when two teams are matched together, we can calculate their Pythagorean difference to find value in matchups. It can be calculated as follows:

The Boston Bruins have a Pwin of 44 and a Pdiff of 4.0. Tomorrow 3/13/12, the Bruins play the Tampa Bay Lightning, who hold a Pdiffof -3.53. Put the two together, the Bruins have a 7.53 game advantage in wins. Looking at their actual records, the Bruins already look like the better team (Lightning are 30-37). Take into account the "luck" and performance factor, the Bruins should be an even more favorable team. By looking at the Pdiffalone, Bruins should win the matchup. However, we must keep in mind that this is the first filter and other statistics, such as goaltending and offensive power must be taken into consideration.

More to come soon.... and for those of you who don't believe in the "luck" factor. Watch the following videos and think about it. You watch enough sports, and you'll start seeing some crazy, unbelievable and WTF moments.

Sunday, March 4, 2012

Welcome to Xeziometrix.
Over the past year and a half or so, I have had several requests from friends
asking me about my approach to sabremetrics and how I evaluate team performance
in professional sports. For those of you who are not familiar with the
concept, just think Moneyball. Using statistics, Billy Beane and
the Oakland A's revolutionized the way baseball is managed and played. Prior to
that, Bill James used mathematical models determine the value of players. I
stumbled upon these ideas a few years ago when I got tired of losing in sports
wagering. How did Las Vegas sports bookies settle on the point spread of a
game? How did they determine the odds of a team winning straight up? These were
some questions I asked myself. In the summer of 2010, with the help of a few people I've gotten to know along the way, I searched for the answers.

Prior to this, I never
really enjoyed watching baseball. It was boring, and I never really understood it.
However, because sabremetrics was founded on the extensiveness of baseball
statistics, that is where I had to start. It was also a great time to start
tracking the sport as the San Francisco Giants went on to secure the World
Series title that year. Call me a bandwagoner if you will.

My approach to
sabremetrics is primarily focused on evaluating a team as a whole and to
predict the winners of each game. I could really care less if Albert Pujols'
10-year contract is really worth $254 million. The goal of this blog is to
demonstrate how to interpret the numbers and to exploit mistakes and public
perception presented by bookies, to evaluate sports wagers and rank sports
teams using algebra and statistics. Just look at the stats and find out what
works and what doesn't. Simple as that. We will explore four major sports: MLB,
NHL, NFL and NBA. Eventually, I will also provide a winning NCAAF system that hit at
a rate of 68% last season. The beauty of this system is, you won't even have to
think for a second when you make these picks.

Also, please be aware that I am no longer
running any analyses nor tracking any games besides my home teams for the upcoming sport seasons. However, it does not mean I
am not paying attention. I will not shut the door on what could be a great opportunity. Let me tell you
now, once you get all these numbers in your head, it is difficult to watch a
game without thinking about it. I am willing to share what I have personally
learned and explain ideas utilized by sabremetricians in hopes that you will be
able to build upon and formulate new ideas. As games evolve and change,
equations and focus will need tweaking as well. There is a saying, "We
cannot direct the wind, but we can adjust the sails." Remember, whatever
is published on the internet, Vegas has access to them. Develop your own
methods to beat the game.

Questions and comments are encouraged. Please feel free to
post to the blog.